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Television signal scrambling method and apparatus

  • US 5,206,907 A
  • Filed: 04/30/1991
  • Issued: 04/27/1993
  • Est. Priority Date: 05/10/1990
  • Status: Expired due to Fees
First Claim
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1. A scrambling apparatus of a television signal including a video signal and an audio signal, comprising:

  • analog-to-digital conversion means for converting a first video signal to a digital signal;

    memory means for storing the digital signal;

    timing generating means for providing a write clock and a read clock to the memory means to write the digital signal to and read the digital signal from the memory means, the provision of the read clock or write clock being temporarily suspended so that a corresponding part of the read-out digital signal is elongated or shortened, respectively, to change the length of a line of the video signal;

    digital-to-analog conversion means for converting the digital signal output from the memory means to a second video signal; and

    scrambling means for compressing a horizontal sync signal portion and/or a vertical blanking interval portion of the second video signal by a predetermined amount.

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